From 0a6c701f92e1aa368c44632fa0985e92703354ed Mon Sep 17 00:00:00 2001
From: Yangbo Lu <yangbo.lu@nxp.com>
Date: Wed, 17 Jan 2018 15:35:48 +0800
Subject: [PATCH 22/30] iommu: support layerscape

This is an integrated patch for layerscape smmu support.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
---
 drivers/iommu/amd_iommu.c    |  56 ++++++----
 drivers/iommu/arm-smmu-v3.c  | 111 ++++++++++++++------
 drivers/iommu/arm-smmu.c     | 100 +++++++++++++++---
 drivers/iommu/dma-iommu.c    | 242 ++++++++++++++++++++++++++++++++++++-------
 drivers/iommu/intel-iommu.c  |  92 ++++++++++++----
 drivers/iommu/iommu.c        | 219 ++++++++++++++++++++++++++++++++++++---
 drivers/iommu/mtk_iommu.c    |   2 +
 drivers/iommu/mtk_iommu_v1.c |   2 +
 include/linux/dma-iommu.h    |  11 ++
 include/linux/iommu.h        |  55 +++++++---
 10 files changed, 739 insertions(+), 151 deletions(-)

--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -379,6 +379,8 @@ static struct iommu_group *acpihid_devic
 
 	if (!entry->group)
 		entry->group = generic_device_group(dev);
+	else
+		iommu_group_ref_get(entry->group);
 
 	return entry->group;
 }
@@ -3166,9 +3168,10 @@ static bool amd_iommu_capable(enum iommu
 	return false;
 }
 
-static void amd_iommu_get_dm_regions(struct device *dev,
-				     struct list_head *head)
+static void amd_iommu_get_resv_regions(struct device *dev,
+				       struct list_head *head)
 {
+	struct iommu_resv_region *region;
 	struct unity_map_entry *entry;
 	int devid;
 
@@ -3177,41 +3180,56 @@ static void amd_iommu_get_dm_regions(str
 		return;
 
 	list_for_each_entry(entry, &amd_iommu_unity_map, list) {
-		struct iommu_dm_region *region;
+		size_t length;
+		int prot = 0;
 
 		if (devid < entry->devid_start || devid > entry->devid_end)
 			continue;
 
-		region = kzalloc(sizeof(*region), GFP_KERNEL);
+		length = entry->address_end - entry->address_start;
+		if (entry->prot & IOMMU_PROT_IR)
+			prot |= IOMMU_READ;
+		if (entry->prot & IOMMU_PROT_IW)
+			prot |= IOMMU_WRITE;
+
+		region = iommu_alloc_resv_region(entry->address_start,
+						 length, prot,
+						 IOMMU_RESV_DIRECT);
 		if (!region) {
 			pr_err("Out of memory allocating dm-regions for %s\n",
 				dev_name(dev));
 			return;
 		}
-
-		region->start = entry->address_start;
-		region->length = entry->address_end - entry->address_start;
-		if (entry->prot & IOMMU_PROT_IR)
-			region->prot |= IOMMU_READ;
-		if (entry->prot & IOMMU_PROT_IW)
-			region->prot |= IOMMU_WRITE;
-
 		list_add_tail(&region->list, head);
 	}
+
+	region = iommu_alloc_resv_region(MSI_RANGE_START,
+					 MSI_RANGE_END - MSI_RANGE_START + 1,
+					 0, IOMMU_RESV_MSI);
+	if (!region)
+		return;
+	list_add_tail(&region->list, head);
+
+	region = iommu_alloc_resv_region(HT_RANGE_START,
+					 HT_RANGE_END - HT_RANGE_START + 1,
+					 0, IOMMU_RESV_RESERVED);
+	if (!region)
+		return;
+	list_add_tail(&region->list, head);
 }
 
-static void amd_iommu_put_dm_regions(struct device *dev,
+static void amd_iommu_put_resv_regions(struct device *dev,
 				     struct list_head *head)
 {
-	struct iommu_dm_region *entry, *next;
+	struct iommu_resv_region *entry, *next;
 
 	list_for_each_entry_safe(entry, next, head, list)
 		kfree(entry);
 }
 
-static void amd_iommu_apply_dm_region(struct device *dev,
+static void amd_iommu_apply_resv_region(struct device *dev,
 				      struct iommu_domain *domain,
-				      struct iommu_dm_region *region)
+				      struct iommu_resv_region *region)
 {
 	struct dma_ops_domain *dma_dom = to_dma_ops_domain(to_pdomain(domain));
 	unsigned long start, end;
@@ -3235,9 +3253,9 @@ static const struct iommu_ops amd_iommu_
 	.add_device = amd_iommu_add_device,
 	.remove_device = amd_iommu_remove_device,
 	.device_group = amd_iommu_device_group,
-	.get_dm_regions = amd_iommu_get_dm_regions,
-	.put_dm_regions = amd_iommu_put_dm_regions,
-	.apply_dm_region = amd_iommu_apply_dm_region,
+	.get_resv_regions = amd_iommu_get_resv_regions,
+	.put_resv_regions = amd_iommu_put_resv_regions,
+	.apply_resv_region = amd_iommu_apply_resv_region,
 	.pgsize_bitmap	= AMD_IOMMU_PGSIZES,
 };
 
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -410,6 +410,9 @@
 /* High-level queue structures */
 #define ARM_SMMU_POLL_TIMEOUT_US	100
 
+#define MSI_IOVA_BASE			0x8000000
+#define MSI_IOVA_LENGTH			0x100000
+
 static bool disable_bypass;
 module_param_named(disable_bypass, disable_bypass, bool, S_IRUGO);
 MODULE_PARM_DESC(disable_bypass,
@@ -552,9 +555,14 @@ struct arm_smmu_s2_cfg {
 };
 
 struct arm_smmu_strtab_ent {
-	bool				valid;
-
-	bool				bypass;	/* Overrides s1/s2 config */
+	/*
+	 * An STE is "assigned" if the master emitting the corresponding SID
+	 * is attached to a domain. The behaviour of an unassigned STE is
+	 * determined by the disable_bypass parameter, whereas an assigned
+	 * STE behaves according to s1_cfg/s2_cfg, which themselves are
+	 * configured according to the domain type.
+	 */
+	bool				assigned;
 	struct arm_smmu_s1_cfg		*s1_cfg;
 	struct arm_smmu_s2_cfg		*s2_cfg;
 };
@@ -627,6 +635,7 @@ enum arm_smmu_domain_stage {
 	ARM_SMMU_DOMAIN_S1 = 0,
 	ARM_SMMU_DOMAIN_S2,
 	ARM_SMMU_DOMAIN_NESTED,
+	ARM_SMMU_DOMAIN_BYPASS,
 };
 
 struct arm_smmu_domain {
@@ -1000,9 +1009,9 @@ static void arm_smmu_write_strtab_ent(st
 	 * This is hideously complicated, but we only really care about
 	 * three cases at the moment:
 	 *
-	 * 1. Invalid (all zero) -> bypass  (init)
-	 * 2. Bypass -> translation (attach)
-	 * 3. Translation -> bypass (detach)
+	 * 1. Invalid (all zero) -> bypass/fault (init)
+	 * 2. Bypass/fault -> translation/bypass (attach)
+	 * 3. Translation/bypass -> bypass/fault (detach)
 	 *
 	 * Given that we can't update the STE atomically and the SMMU
 	 * doesn't read the thing in a defined order, that leaves us
@@ -1041,11 +1050,15 @@ static void arm_smmu_write_strtab_ent(st
 	}
 
 	/* Nuke the existing STE_0 value, as we're going to rewrite it */
-	val = ste->valid ? STRTAB_STE_0_V : 0;
+	val = STRTAB_STE_0_V;
+
+	/* Bypass/fault */
+	if (!ste->assigned || !(ste->s1_cfg || ste->s2_cfg)) {
+		if (!ste->assigned && disable_bypass)
+			val |= STRTAB_STE_0_CFG_ABORT;
+		else
+			val |= STRTAB_STE_0_CFG_BYPASS;
 
-	if (ste->bypass) {
-		val |= disable_bypass ? STRTAB_STE_0_CFG_ABORT
-				      : STRTAB_STE_0_CFG_BYPASS;
 		dst[0] = cpu_to_le64(val);
 		dst[1] = cpu_to_le64(STRTAB_STE_1_SHCFG_INCOMING
 			 << STRTAB_STE_1_SHCFG_SHIFT);
@@ -1108,10 +1121,7 @@ static void arm_smmu_write_strtab_ent(st
 static void arm_smmu_init_bypass_stes(u64 *strtab, unsigned int nent)
 {
 	unsigned int i;
-	struct arm_smmu_strtab_ent ste = {
-		.valid	= true,
-		.bypass	= true,
-	};
+	struct arm_smmu_strtab_ent ste = { .assigned = false };
 
 	for (i = 0; i < nent; ++i) {
 		arm_smmu_write_strtab_ent(NULL, -1, strtab, &ste);
@@ -1365,8 +1375,6 @@ static bool arm_smmu_capable(enum iommu_
 	switch (cap) {
 	case IOMMU_CAP_CACHE_COHERENCY:
 		return true;
-	case IOMMU_CAP_INTR_REMAP:
-		return true; /* MSIs are just memory writes */
 	case IOMMU_CAP_NOEXEC:
 		return true;
 	default:
@@ -1378,7 +1386,9 @@ static struct iommu_domain *arm_smmu_dom
 {
 	struct arm_smmu_domain *smmu_domain;
 
-	if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
+	if (type != IOMMU_DOMAIN_UNMANAGED &&
+	    type != IOMMU_DOMAIN_DMA &&
+	    type != IOMMU_DOMAIN_IDENTITY)
 		return NULL;
 
 	/*
@@ -1509,6 +1519,11 @@ static int arm_smmu_domain_finalise(stru
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 	struct arm_smmu_device *smmu = smmu_domain->smmu;
 
+	if (domain->type == IOMMU_DOMAIN_IDENTITY) {
+		smmu_domain->stage = ARM_SMMU_DOMAIN_BYPASS;
+		return 0;
+	}
+
 	/* Restrict the stage to what we can actually support */
 	if (!(smmu->features & ARM_SMMU_FEAT_TRANS_S1))
 		smmu_domain->stage = ARM_SMMU_DOMAIN_S2;
@@ -1581,7 +1596,7 @@ static __le64 *arm_smmu_get_step_for_sid
 	return step;
 }
 
-static int arm_smmu_install_ste_for_dev(struct iommu_fwspec *fwspec)
+static void arm_smmu_install_ste_for_dev(struct iommu_fwspec *fwspec)
 {
 	int i, j;
 	struct arm_smmu_master_data *master = fwspec->iommu_priv;
@@ -1600,17 +1615,14 @@ static int arm_smmu_install_ste_for_dev(
 
 		arm_smmu_write_strtab_ent(smmu, sid, step, &master->ste);
 	}
-
-	return 0;
 }
 
 static void arm_smmu_detach_dev(struct device *dev)
 {
 	struct arm_smmu_master_data *master = dev->iommu_fwspec->iommu_priv;
 
-	master->ste.bypass = true;
-	if (arm_smmu_install_ste_for_dev(dev->iommu_fwspec) < 0)
-		dev_warn(dev, "failed to install bypass STE\n");
+	master->ste.assigned = false;
+	arm_smmu_install_ste_for_dev(dev->iommu_fwspec);
 }
 
 static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
@@ -1629,7 +1641,7 @@ static int arm_smmu_attach_dev(struct io
 	ste = &master->ste;
 
 	/* Already attached to a different domain? */
-	if (!ste->bypass)
+	if (ste->assigned)
 		arm_smmu_detach_dev(dev);
 
 	mutex_lock(&smmu_domain->init_mutex);
@@ -1650,10 +1662,12 @@ static int arm_smmu_attach_dev(struct io
 		goto out_unlock;
 	}
 
-	ste->bypass = false;
-	ste->valid = true;
+	ste->assigned = true;
 
-	if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
+	if (smmu_domain->stage == ARM_SMMU_DOMAIN_BYPASS) {
+		ste->s1_cfg = NULL;
+		ste->s2_cfg = NULL;
+	} else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
 		ste->s1_cfg = &smmu_domain->s1_cfg;
 		ste->s2_cfg = NULL;
 		arm_smmu_write_ctx_desc(smmu, ste->s1_cfg);
@@ -1662,10 +1676,7 @@ static int arm_smmu_attach_dev(struct io
 		ste->s2_cfg = &smmu_domain->s2_cfg;
 	}
 
-	ret = arm_smmu_install_ste_for_dev(dev->iommu_fwspec);
-	if (ret < 0)
-		ste->valid = false;
-
+	arm_smmu_install_ste_for_dev(dev->iommu_fwspec);
 out_unlock:
 	mutex_unlock(&smmu_domain->init_mutex);
 	return ret;
@@ -1713,6 +1724,9 @@ arm_smmu_iova_to_phys(struct iommu_domai
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 	struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops;
 
+	if (domain->type == IOMMU_DOMAIN_IDENTITY)
+		return iova;
+
 	if (!ops)
 		return 0;
 
@@ -1811,7 +1825,7 @@ static void arm_smmu_remove_device(struc
 		return;
 
 	master = fwspec->iommu_priv;
-	if (master && master->ste.valid)
+	if (master && master->ste.assigned)
 		arm_smmu_detach_dev(dev);
 	iommu_group_remove_device(dev);
 	kfree(master);
@@ -1840,6 +1854,9 @@ static int arm_smmu_domain_get_attr(stru
 {
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 
+	if (domain->type != IOMMU_DOMAIN_UNMANAGED)
+		return -EINVAL;
+
 	switch (attr) {
 	case DOMAIN_ATTR_NESTING:
 		*(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
@@ -1855,6 +1872,9 @@ static int arm_smmu_domain_set_attr(stru
 	int ret = 0;
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 
+	if (domain->type != IOMMU_DOMAIN_UNMANAGED)
+		return -EINVAL;
+
 	mutex_lock(&smmu_domain->init_mutex);
 
 	switch (attr) {
@@ -1884,6 +1904,31 @@ static int arm_smmu_of_xlate(struct devi
 	return iommu_fwspec_add_ids(dev, args->args, 1);
 }
 
+static void arm_smmu_get_resv_regions(struct device *dev,
+				      struct list_head *head)
+{
+	struct iommu_resv_region *region;
+	int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
+
+	region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH,
+					 prot, IOMMU_RESV_SW_MSI);
+	if (!region)
+		return;
+
+	list_add_tail(&region->list, head);
+
+	iommu_dma_get_resv_regions(dev, head);
+}
+
+static void arm_smmu_put_resv_regions(struct device *dev,
+				      struct list_head *head)
+{
+	struct iommu_resv_region *entry, *next;
+
+	list_for_each_entry_safe(entry, next, head, list)
+		kfree(entry);
+}
+
 static struct iommu_ops arm_smmu_ops = {
 	.capable		= arm_smmu_capable,
 	.domain_alloc		= arm_smmu_domain_alloc,
@@ -1899,6 +1944,8 @@ static struct iommu_ops arm_smmu_ops = {
 	.domain_get_attr	= arm_smmu_domain_get_attr,
 	.domain_set_attr	= arm_smmu_domain_set_attr,
 	.of_xlate		= arm_smmu_of_xlate,
+	.get_resv_regions	= arm_smmu_get_resv_regions,
+	.put_resv_regions	= arm_smmu_put_resv_regions,
 	.pgsize_bitmap		= -1UL, /* Restricted during device attach */
 };
 
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -49,6 +49,7 @@
 #include <linux/spinlock.h>
 
 #include <linux/amba/bus.h>
+#include "../staging/fsl-mc/include/mc-bus.h"
 
 #include "io-pgtable.h"
 
@@ -247,6 +248,7 @@ enum arm_smmu_s2cr_privcfg {
 #define ARM_MMU500_ACTLR_CPRE		(1 << 1)
 
 #define ARM_MMU500_ACR_CACHE_LOCK	(1 << 26)
+#define ARM_MMU500_ACR_SMTNMB_TLBEN	(1 << 8)
 
 #define CB_PAR_F			(1 << 0)
 
@@ -278,6 +280,9 @@ enum arm_smmu_s2cr_privcfg {
 
 #define FSYNR0_WNR			(1 << 4)
 
+#define MSI_IOVA_BASE			0x8000000
+#define MSI_IOVA_LENGTH			0x100000
+
 static int force_stage;
 module_param(force_stage, int, S_IRUGO);
 MODULE_PARM_DESC(force_stage,
@@ -401,6 +406,7 @@ enum arm_smmu_domain_stage {
 	ARM_SMMU_DOMAIN_S1 = 0,
 	ARM_SMMU_DOMAIN_S2,
 	ARM_SMMU_DOMAIN_NESTED,
+	ARM_SMMU_DOMAIN_BYPASS,
 };
 
 struct arm_smmu_domain {
@@ -821,6 +827,12 @@ static int arm_smmu_init_domain_context(
 	if (smmu_domain->smmu)
 		goto out_unlock;
 
+	if (domain->type == IOMMU_DOMAIN_IDENTITY) {
+		smmu_domain->stage = ARM_SMMU_DOMAIN_BYPASS;
+		smmu_domain->smmu = smmu;
+		goto out_unlock;
+	}
+
 	/*
 	 * Mapping the requested stage onto what we support is surprisingly
 	 * complicated, mainly because the spec allows S1+S2 SMMUs without
@@ -981,7 +993,7 @@ static void arm_smmu_destroy_domain_cont
 	void __iomem *cb_base;
 	int irq;
 
-	if (!smmu)
+	if (!smmu || domain->type == IOMMU_DOMAIN_IDENTITY)
 		return;
 
 	/*
@@ -1004,7 +1016,9 @@ static struct iommu_domain *arm_smmu_dom
 {
 	struct arm_smmu_domain *smmu_domain;
 
-	if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
+	if (type != IOMMU_DOMAIN_UNMANAGED &&
+	    type != IOMMU_DOMAIN_DMA &&
+	    type != IOMMU_DOMAIN_IDENTITY)
 		return NULL;
 	/*
 	 * Allocate the domain and initialise some of its data structures.
@@ -1202,10 +1216,15 @@ static int arm_smmu_domain_add_master(st
 {
 	struct arm_smmu_device *smmu = smmu_domain->smmu;
 	struct arm_smmu_s2cr *s2cr = smmu->s2crs;
-	enum arm_smmu_s2cr_type type = S2CR_TYPE_TRANS;
 	u8 cbndx = smmu_domain->cfg.cbndx;
+	enum arm_smmu_s2cr_type type;
 	int i, idx;
 
+	if (smmu_domain->stage == ARM_SMMU_DOMAIN_BYPASS)
+		type = S2CR_TYPE_BYPASS;
+	else
+		type = S2CR_TYPE_TRANS;
+
 	for_each_cfg_sme(fwspec, i, idx) {
 		if (type == s2cr[idx].type && cbndx == s2cr[idx].cbndx)
 			continue;
@@ -1343,6 +1362,9 @@ static phys_addr_t arm_smmu_iova_to_phys
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 	struct io_pgtable_ops *ops= smmu_domain->pgtbl_ops;
 
+	if (domain->type == IOMMU_DOMAIN_IDENTITY)
+		return iova;
+
 	if (!ops)
 		return 0;
 
@@ -1368,8 +1390,6 @@ static bool arm_smmu_capable(enum iommu_
 		 * requests.
 		 */
 		return true;
-	case IOMMU_CAP_INTR_REMAP:
-		return true; /* MSIs are just memory writes */
 	case IOMMU_CAP_NOEXEC:
 		return true;
 	default:
@@ -1478,10 +1498,12 @@ static struct iommu_group *arm_smmu_devi
 	}
 
 	if (group)
-		return group;
+		return iommu_group_ref_get(group);
 
 	if (dev_is_pci(dev))
 		group = pci_device_group(dev);
+	else if (dev_is_fsl_mc(dev))
+		group = fsl_mc_device_group(dev);
 	else
 		group = generic_device_group(dev);
 
@@ -1493,6 +1515,9 @@ static int arm_smmu_domain_get_attr(stru
 {
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 
+	if (domain->type != IOMMU_DOMAIN_UNMANAGED)
+		return -EINVAL;
+
 	switch (attr) {
 	case DOMAIN_ATTR_NESTING:
 		*(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
@@ -1508,6 +1533,9 @@ static int arm_smmu_domain_set_attr(stru
 	int ret = 0;
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 
+	if (domain->type != IOMMU_DOMAIN_UNMANAGED)
+		return -EINVAL;
+
 	mutex_lock(&smmu_domain->init_mutex);
 
 	switch (attr) {
@@ -1534,17 +1562,44 @@ out_unlock:
 
 static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args)
 {
-	u32 fwid = 0;
+	u32 mask, fwid = 0;
 
 	if (args->args_count > 0)
 		fwid |= (u16)args->args[0];
 
 	if (args->args_count > 1)
 		fwid |= (u16)args->args[1] << SMR_MASK_SHIFT;
+	else if (!of_property_read_u32(args->np, "stream-match-mask", &mask))
+		fwid |= (u16)mask << SMR_MASK_SHIFT;
 
 	return iommu_fwspec_add_ids(dev, &fwid, 1);
 }
 
+static void arm_smmu_get_resv_regions(struct device *dev,
+				      struct list_head *head)
+{
+	struct iommu_resv_region *region;
+	int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
+
+	region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH,
+					 prot, IOMMU_RESV_SW_MSI);
+	if (!region)
+		return;
+
+	list_add_tail(&region->list, head);
+
+	iommu_dma_get_resv_regions(dev, head);
+}
+
+static void arm_smmu_put_resv_regions(struct device *dev,
+				      struct list_head *head)
+{
+	struct iommu_resv_region *entry, *next;
+
+	list_for_each_entry_safe(entry, next, head, list)
+		kfree(entry);
+}
+
 static struct iommu_ops arm_smmu_ops = {
 	.capable		= arm_smmu_capable,
 	.domain_alloc		= arm_smmu_domain_alloc,
@@ -1560,6 +1615,8 @@ static struct iommu_ops arm_smmu_ops = {
 	.domain_get_attr	= arm_smmu_domain_get_attr,
 	.domain_set_attr	= arm_smmu_domain_set_attr,
 	.of_xlate		= arm_smmu_of_xlate,
+	.get_resv_regions	= arm_smmu_get_resv_regions,
+	.put_resv_regions	= arm_smmu_put_resv_regions,
 	.pgsize_bitmap		= -1UL, /* Restricted during device attach */
 };
 
@@ -1581,16 +1638,22 @@ static void arm_smmu_device_reset(struct
 	for (i = 0; i < smmu->num_mapping_groups; ++i)
 		arm_smmu_write_sme(smmu, i);
 
-	/*
-	 * Before clearing ARM_MMU500_ACTLR_CPRE, need to
-	 * clear CACHE_LOCK bit of ACR first. And, CACHE_LOCK
-	 * bit is only present in MMU-500r2 onwards.
-	 */
-	reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_ID7);
-	major = (reg >> ID7_MAJOR_SHIFT) & ID7_MAJOR_MASK;
-	if ((smmu->model == ARM_MMU500) && (major >= 2)) {
+	if (smmu->model == ARM_MMU500) {
+		/*
+		 * Before clearing ARM_MMU500_ACTLR_CPRE, need to
+		 * clear CACHE_LOCK bit of ACR first. And, CACHE_LOCK
+		 * bit is only present in MMU-500r2 onwards.
+		 */
+		reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_ID7);
+		major = (reg >> ID7_MAJOR_SHIFT) & ID7_MAJOR_MASK;
 		reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_sACR);
-		reg &= ~ARM_MMU500_ACR_CACHE_LOCK;
+		if (major >= 2)
+			reg &= ~ARM_MMU500_ACR_CACHE_LOCK;
+		/*
+		 * Allow unmatched Stream IDs to allocate bypass
+		 * TLB entries for reduced latency.
+		 */
+		reg |= ARM_MMU500_ACR_SMTNMB_TLBEN;
 		writel_relaxed(reg, gr0_base + ARM_SMMU_GR0_sACR);
 	}
 
@@ -2024,6 +2087,11 @@ static int arm_smmu_device_dt_probe(stru
 		bus_set_iommu(&pci_bus_type, &arm_smmu_ops);
 	}
 #endif
+#ifdef CONFIG_FSL_MC_BUS
+	if (!iommu_present(&fsl_mc_bus_type))
+		bus_set_iommu(&fsl_mc_bus_type, &arm_smmu_ops);
+#endif
+
 	return 0;
 }
 
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -37,15 +37,50 @@ struct iommu_dma_msi_page {
 	phys_addr_t		phys;
 };
 
+enum iommu_dma_cookie_type {
+	IOMMU_DMA_IOVA_COOKIE,
+	IOMMU_DMA_MSI_COOKIE,
+};
+
 struct iommu_dma_cookie {
-	struct iova_domain	iovad;
-	struct list_head	msi_page_list;
-	spinlock_t		msi_lock;
+	enum iommu_dma_cookie_type	type;
+	union {
+		/* Full allocator for IOMMU_DMA_IOVA_COOKIE */
+		struct iova_domain	iovad;
+		/* Trivial linear page allocator for IOMMU_DMA_MSI_COOKIE */
+		dma_addr_t		msi_iova;
+	};
+	struct list_head		msi_page_list;
+	spinlock_t			msi_lock;
 };
 
+static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)
+{
+	if (cookie->type == IOMMU_DMA_IOVA_COOKIE)
+		return cookie->iovad.granule;
+	return PAGE_SIZE;
+}
+
 static inline struct iova_domain *cookie_iovad(struct iommu_domain *domain)
 {
-	return &((struct iommu_dma_cookie *)domain->iova_cookie)->iovad;
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+
+	if (cookie->type == IOMMU_DMA_IOVA_COOKIE)
+		return &cookie->iovad;
+	return NULL;
+}
+
+static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type)
+{
+	struct iommu_dma_cookie *cookie;
+
+	cookie = kzalloc(sizeof(*cookie), GFP_KERNEL);
+	if (cookie) {
+		spin_lock_init(&cookie->msi_lock);
+		INIT_LIST_HEAD(&cookie->msi_page_list);
+		cookie->type = type;
+	}
+	return cookie;
 }
 
 int iommu_dma_init(void)
@@ -62,25 +97,53 @@ int iommu_dma_init(void)
  */
 int iommu_get_dma_cookie(struct iommu_domain *domain)
 {
+	if (domain->iova_cookie)
+		return -EEXIST;
+
+	domain->iova_cookie = cookie_alloc(IOMMU_DMA_IOVA_COOKIE);
+	if (!domain->iova_cookie)
+		return -ENOMEM;
+
+	return 0;
+}
+EXPORT_SYMBOL(iommu_get_dma_cookie);
+
+/**
+ * iommu_get_msi_cookie - Acquire just MSI remapping resources
+ * @domain: IOMMU domain to prepare
+ * @base: Start address of IOVA region for MSI mappings
+ *
+ * Users who manage their own IOVA allocation and do not want DMA API support,
+ * but would still like to take advantage of automatic MSI remapping, can use
+ * this to initialise their own domain appropriately. Users should reserve a
+ * contiguous IOVA region, starting at @base, large enough to accommodate the
+ * number of PAGE_SIZE mappings necessary to cover every MSI doorbell address
+ * used by the devices attached to @domain.
+ */
+int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
+{
 	struct iommu_dma_cookie *cookie;
 
+	if (domain->type != IOMMU_DOMAIN_UNMANAGED)
+		return -EINVAL;
+
 	if (domain->iova_cookie)
 		return -EEXIST;
 
-	cookie = kzalloc(sizeof(*cookie), GFP_KERNEL);
+	cookie = cookie_alloc(IOMMU_DMA_MSI_COOKIE);
 	if (!cookie)
 		return -ENOMEM;
 
-	spin_lock_init(&cookie->msi_lock);
-	INIT_LIST_HEAD(&cookie->msi_page_list);
+	cookie->msi_iova = base;
 	domain->iova_cookie = cookie;
 	return 0;
 }
-EXPORT_SYMBOL(iommu_get_dma_cookie);
+EXPORT_SYMBOL(iommu_get_msi_cookie);
 
 /**
  * iommu_put_dma_cookie - Release a domain's DMA mapping resources
- * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()
+ * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() or
+ *          iommu_get_msi_cookie()
  *
  * IOMMU drivers should normally call this from their domain_free callback.
  */
@@ -92,7 +155,7 @@ void iommu_put_dma_cookie(struct iommu_d
 	if (!cookie)
 		return;
 
-	if (cookie->iovad.granule)
+	if (cookie->type == IOMMU_DMA_IOVA_COOKIE && cookie->iovad.granule)
 		put_iova_domain(&cookie->iovad);
 
 	list_for_each_entry_safe(msi, tmp, &cookie->msi_page_list, list) {
@@ -104,21 +167,99 @@ void iommu_put_dma_cookie(struct iommu_d
 }
 EXPORT_SYMBOL(iommu_put_dma_cookie);
 
-static void iova_reserve_pci_windows(struct pci_dev *dev,
-		struct iova_domain *iovad)
+/**
+ * iommu_dma_get_resv_regions - Reserved region driver helper
+ * @dev: Device from iommu_get_resv_regions()
+ * @list: Reserved region list from iommu_get_resv_regions()
+ *
+ * IOMMU drivers can use this to implement their .get_resv_regions callback
+ * for general non-IOMMU-specific reservations. Currently, this covers host
+ * bridge windows for PCI devices.
+ */
+void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
 {
-	struct pci_host_bridge *bridge = pci_find_host_bridge(dev->bus);
+	struct pci_host_bridge *bridge;
 	struct resource_entry *window;
-	unsigned long lo, hi;
 
+	if (!dev_is_pci(dev))
+		return;
+
+	bridge = pci_find_host_bridge(to_pci_dev(dev)->bus);
 	resource_list_for_each_entry(window, &bridge->windows) {
+		struct iommu_resv_region *region;
+		phys_addr_t start;
+		size_t length;
+
 		if (resource_type(window->res) != IORESOURCE_MEM)
 			continue;
 
-		lo = iova_pfn(iovad, window->res->start - window->offset);
-		hi = iova_pfn(iovad, window->res->end - window->offset);
+		start = window->res->start - window->offset;
+		length = window->res->end - window->res->start + 1;
+		region = iommu_alloc_resv_region(start, length, 0,
+				IOMMU_RESV_RESERVED);
+		if (!region)
+			return;
+
+		list_add_tail(&region->list, list);
+	}
+}
+EXPORT_SYMBOL(iommu_dma_get_resv_regions);
+
+static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie,
+		phys_addr_t start, phys_addr_t end)
+{
+	struct iova_domain *iovad = &cookie->iovad;
+	struct iommu_dma_msi_page *msi_page;
+	int i, num_pages;
+
+	start -= iova_offset(iovad, start);
+	num_pages = iova_align(iovad, end - start) >> iova_shift(iovad);
+
+	msi_page = kcalloc(num_pages, sizeof(*msi_page), GFP_KERNEL);
+	if (!msi_page)
+		return -ENOMEM;
+
+	for (i = 0; i < num_pages; i++) {
+		msi_page[i].phys = start;
+		msi_page[i].iova = start;
+		INIT_LIST_HEAD(&msi_page[i].list);
+		list_add(&msi_page[i].list, &cookie->msi_page_list);
+		start += iovad->granule;
+	}
+
+	return 0;
+}
+
+static int iova_reserve_iommu_regions(struct device *dev,
+		struct iommu_domain *domain)
+{
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
+	struct iommu_resv_region *region;
+	LIST_HEAD(resv_regions);
+	int ret = 0;
+
+	iommu_get_resv_regions(dev, &resv_regions);
+	list_for_each_entry(region, &resv_regions, list) {
+		unsigned long lo, hi;
+
+		/* We ARE the software that manages these! */
+		if (region->type == IOMMU_RESV_SW_MSI)
+			continue;
+
+		lo = iova_pfn(iovad, region->start);
+		hi = iova_pfn(iovad, region->start + region->length - 1);
 		reserve_iova(iovad, lo, hi);
+
+		if (region->type == IOMMU_RESV_MSI)
+			ret = cookie_init_hw_msi_region(cookie, region->start,
+					region->start + region->length);
+		if (ret)
+			break;
 	}
+	iommu_put_resv_regions(dev, &resv_regions);
+
+	return ret;
 }
 
 /**
@@ -136,11 +277,12 @@ static void iova_reserve_pci_windows(str
 int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 		u64 size, struct device *dev)
 {
-	struct iova_domain *iovad = cookie_iovad(domain);
+	struct iommu_dma_cookie *cookie = domain->iova_cookie;
+	struct iova_domain *iovad = &cookie->iovad;
 	unsigned long order, base_pfn, end_pfn;
 
-	if (!iovad)
-		return -ENODEV;
+	if (!cookie || cookie->type != IOMMU_DMA_IOVA_COOKIE)
+		return -EINVAL;
 
 	/* Use the smallest supported page size for IOVA granularity */
 	order = __ffs(domain->pgsize_bitmap);
@@ -160,22 +302,37 @@ int iommu_dma_init_domain(struct iommu_d
 		end_pfn = min_t(unsigned long, end_pfn,
 				domain->geometry.aperture_end >> order);
 	}
+	/*
+	 * PCI devices may have larger DMA masks, but still prefer allocating
+	 * within a 32-bit mask to avoid DAC addressing. Such limitations don't
+	 * apply to the typical platform device, so for those we may as well
+	 * leave the cache limit at the top of their range to save an rb_last()
+	 * traversal on every allocation.
+	 */
+	if (dev && dev_is_pci(dev))
+		end_pfn &= DMA_BIT_MASK(32) >> order;
 
-	/* All we can safely do with an existing domain is enlarge it */
+	/* start_pfn is always nonzero for an already-initialised domain */
 	if (iovad->start_pfn) {
 		if (1UL << order != iovad->granule ||
-		    base_pfn != iovad->start_pfn ||
-		    end_pfn < iovad->dma_32bit_pfn) {
+		    base_pfn != iovad->start_pfn) {
 			pr_warn("Incompatible range for DMA domain\n");
 			return -EFAULT;
 		}
-		iovad->dma_32bit_pfn = end_pfn;
-	} else {
-		init_iova_domain(iovad, 1UL << order, base_pfn, end_pfn);
-		if (dev && dev_is_pci(dev))
-			iova_reserve_pci_windows(to_pci_dev(dev), iovad);
+		/*
+		 * If we have devices with different DMA masks, move the free
+		 * area cache limit down for the benefit of the smaller one.
+		 */
+		iovad->dma_32bit_pfn = min(end_pfn, iovad->dma_32bit_pfn);
+
+		return 0;
 	}
-	return 0;
+
+	init_iova_domain(iovad, 1UL << order, base_pfn, end_pfn);
+	if (!dev)
+		return 0;
+
+	return iova_reserve_iommu_regions(dev, domain);
 }
 EXPORT_SYMBOL(iommu_dma_init_domain);
 
@@ -643,11 +800,12 @@ static struct iommu_dma_msi_page *iommu_
 {
 	struct iommu_dma_cookie *cookie = domain->iova_cookie;
 	struct iommu_dma_msi_page *msi_page;
-	struct iova_domain *iovad = &cookie->iovad;
+	struct iova_domain *iovad = cookie_iovad(domain);
 	struct iova *iova;
 	int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
+	size_t size = cookie_msi_granule(cookie);
 
-	msi_addr &= ~(phys_addr_t)iova_mask(iovad);
+	msi_addr &= ~(phys_addr_t)(size - 1);
 	list_for_each_entry(msi_page, &cookie->msi_page_list, list)
 		if (msi_page->phys == msi_addr)
 			return msi_page;
@@ -656,13 +814,18 @@ static struct iommu_dma_msi_page *iommu_
 	if (!msi_page)
 		return NULL;
 
-	iova = __alloc_iova(domain, iovad->granule, dma_get_mask(dev));
-	if (!iova)
-		goto out_free_page;
-
 	msi_page->phys = msi_addr;
-	msi_page->iova = iova_dma_addr(iovad, iova);
-	if (iommu_map(domain, msi_page->iova, msi_addr, iovad->granule, prot))
+	if (iovad) {
+		iova = __alloc_iova(domain, size, dma_get_mask(dev));
+		if (!iova)
+			goto out_free_page;
+		msi_page->iova = iova_dma_addr(iovad, iova);
+	} else {
+		msi_page->iova = cookie->msi_iova;
+		cookie->msi_iova += size;
+	}
+
+	if (iommu_map(domain, msi_page->iova, msi_addr, size, prot))
 		goto out_free_iova;
 
 	INIT_LIST_HEAD(&msi_page->list);
@@ -670,7 +833,10 @@ static struct iommu_dma_msi_page *iommu_
 	return msi_page;
 
 out_free_iova:
-	__free_iova(iovad, iova);
+	if (iovad)
+		__free_iova(iovad, iova);
+	else
+		cookie->msi_iova -= size;
 out_free_page:
 	kfree(msi_page);
 	return NULL;
@@ -711,7 +877,7 @@ void iommu_dma_map_msi_msg(int irq, stru
 		msg->data = ~0U;
 	} else {
 		msg->address_hi = upper_32_bits(msi_page->iova);
-		msg->address_lo &= iova_mask(&cookie->iovad);
+		msg->address_lo &= cookie_msi_granule(cookie) - 1;
 		msg->address_lo += lower_32_bits(msi_page->iova);
 	}
 }
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -441,6 +441,7 @@ struct dmar_rmrr_unit {
 	u64	end_address;		/* reserved end address */
 	struct dmar_dev_scope *devices;	/* target devices */
 	int	devices_cnt;		/* target device count */
+	struct iommu_resv_region *resv; /* reserved region handle */
 };
 
 struct dmar_atsr_unit {
@@ -4267,27 +4268,40 @@ static inline void init_iommu_pm_ops(voi
 int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg)
 {
 	struct acpi_dmar_reserved_memory *rmrr;
+	int prot = DMA_PTE_READ|DMA_PTE_WRITE;
 	struct dmar_rmrr_unit *rmrru;
+	size_t length;
 
 	rmrru = kzalloc(sizeof(*rmrru), GFP_KERNEL);
 	if (!rmrru)
-		return -ENOMEM;
+		goto out;
 
 	rmrru->hdr = header;
 	rmrr = (struct acpi_dmar_reserved_memory *)header;
 	rmrru->base_address = rmrr->base_address;
 	rmrru->end_address = rmrr->end_address;
+
+	length = rmrr->end_address - rmrr->base_address + 1;
+	rmrru->resv = iommu_alloc_resv_region(rmrr->base_address, length, prot,
+					      IOMMU_RESV_DIRECT);
+	if (!rmrru->resv)
+		goto free_rmrru;
+
 	rmrru->devices = dmar_alloc_dev_scope((void *)(rmrr + 1),
 				((void *)rmrr) + rmrr->header.length,
 				&rmrru->devices_cnt);
-	if (rmrru->devices_cnt && rmrru->devices == NULL) {
-		kfree(rmrru);
-		return -ENOMEM;
-	}
+	if (rmrru->devices_cnt && rmrru->devices == NULL)
+		goto free_all;
 
 	list_add(&rmrru->list, &dmar_rmrr_units);
 
 	return 0;
+free_all:
+	kfree(rmrru->resv);
+free_rmrru:
+	kfree(rmrru);
+out:
+	return -ENOMEM;
 }
 
 static struct dmar_atsr_unit *dmar_find_atsr(struct acpi_dmar_atsr *atsr)
@@ -4501,6 +4515,7 @@ static void intel_iommu_free_dmars(void)
 	list_for_each_entry_safe(rmrru, rmrr_n, &dmar_rmrr_units, list) {
 		list_del(&rmrru->list);
 		dmar_free_dev_scope(&rmrru->devices, &rmrru->devices_cnt);
+		kfree(rmrru->resv);
 		kfree(rmrru);
 	}
 
@@ -5236,6 +5251,45 @@ static void intel_iommu_remove_device(st
 	iommu_device_unlink(iommu->iommu_dev, dev);
 }
 
+static void intel_iommu_get_resv_regions(struct device *device,
+					 struct list_head *head)
+{
+	struct iommu_resv_region *reg;
+	struct dmar_rmrr_unit *rmrr;
+	struct device *i_dev;
+	int i;
+
+	rcu_read_lock();
+	for_each_rmrr_units(rmrr) {
+		for_each_active_dev_scope(rmrr->devices, rmrr->devices_cnt,
+					  i, i_dev) {
+			if (i_dev != device)
+				continue;
+
+			list_add_tail(&rmrr->resv->list, head);
+		}
+	}
+	rcu_read_unlock();
+
+	reg = iommu_alloc_resv_region(IOAPIC_RANGE_START,
+				      IOAPIC_RANGE_END - IOAPIC_RANGE_START + 1,
+				      0, IOMMU_RESV_MSI);
+	if (!reg)
+		return;
+	list_add_tail(&reg->list, head);
+}
+
+static void intel_iommu_put_resv_regions(struct device *dev,
+					 struct list_head *head)
+{
+	struct iommu_resv_region *entry, *next;
+
+	list_for_each_entry_safe(entry, next, head, list) {
+		if (entry->type == IOMMU_RESV_RESERVED)
+			kfree(entry);
+	}
+}
+
 #ifdef CONFIG_INTEL_IOMMU_SVM
 #define MAX_NR_PASID_BITS (20)
 static inline unsigned long intel_iommu_get_pts(struct intel_iommu *iommu)
@@ -5366,19 +5420,21 @@ struct intel_iommu *intel_svm_device_to_
 #endif /* CONFIG_INTEL_IOMMU_SVM */
 
 static const struct iommu_ops intel_iommu_ops = {
-	.capable	= intel_iommu_capable,
-	.domain_alloc	= intel_iommu_domain_alloc,
-	.domain_free	= intel_iommu_domain_free,
-	.attach_dev	= intel_iommu_attach_device,
-	.detach_dev	= intel_iommu_detach_device,
-	.map		= intel_iommu_map,
-	.unmap		= intel_iommu_unmap,
-	.map_sg		= default_iommu_map_sg,
-	.iova_to_phys	= intel_iommu_iova_to_phys,
-	.add_device	= intel_iommu_add_device,
-	.remove_device	= intel_iommu_remove_device,
-	.device_group   = pci_device_group,
-	.pgsize_bitmap	= INTEL_IOMMU_PGSIZES,
+	.capable		= intel_iommu_capable,
+	.domain_alloc		= intel_iommu_domain_alloc,
+	.domain_free		= intel_iommu_domain_free,
+	.attach_dev		= intel_iommu_attach_device,
+	.detach_dev		= intel_iommu_detach_device,
+	.map			= intel_iommu_map,
+	.unmap			= intel_iommu_unmap,
+	.map_sg			= default_iommu_map_sg,
+	.iova_to_phys		= intel_iommu_iova_to_phys,
+	.add_device		= intel_iommu_add_device,
+	.remove_device		= intel_iommu_remove_device,
+	.get_resv_regions	= intel_iommu_get_resv_regions,
+	.put_resv_regions	= intel_iommu_put_resv_regions,
+	.device_group		= pci_device_group,
+	.pgsize_bitmap		= INTEL_IOMMU_PGSIZES,
 };
 
 static void quirk_iommu_g4x_gfx(struct pci_dev *dev)
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -36,6 +36,7 @@
 
 static struct kset *iommu_group_kset;
 static DEFINE_IDA(iommu_group_ida);
+static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_DMA;
 
 struct iommu_callback_data {
 	const struct iommu_ops *ops;
@@ -68,6 +69,13 @@ struct iommu_group_attribute {
 			 const char *buf, size_t count);
 };
 
+static const char * const iommu_group_resv_type_string[] = {
+	[IOMMU_RESV_DIRECT]	= "direct",
+	[IOMMU_RESV_RESERVED]	= "reserved",
+	[IOMMU_RESV_MSI]	= "msi",
+	[IOMMU_RESV_SW_MSI]	= "msi",
+};
+
 #define IOMMU_GROUP_ATTR(_name, _mode, _show, _store)		\
 struct iommu_group_attribute iommu_group_attr_##_name =		\
 	__ATTR(_name, _mode, _show, _store)
@@ -86,6 +94,18 @@ static int __iommu_attach_group(struct i
 static void __iommu_detach_group(struct iommu_domain *domain,
 				 struct iommu_group *group);
 
+static int __init iommu_set_def_domain_type(char *str)
+{
+	bool pt;
+
+	if (!str || strtobool(str, &pt))
+		return -EINVAL;
+
+	iommu_def_domain_type = pt ? IOMMU_DOMAIN_IDENTITY : IOMMU_DOMAIN_DMA;
+	return 0;
+}
+early_param("iommu.passthrough", iommu_set_def_domain_type);
+
 static ssize_t iommu_group_attr_show(struct kobject *kobj,
 				     struct attribute *__attr, char *buf)
 {
@@ -133,8 +153,131 @@ static ssize_t iommu_group_show_name(str
 	return sprintf(buf, "%s\n", group->name);
 }
 
+/**
+ * iommu_insert_resv_region - Insert a new region in the
+ * list of reserved regions.
+ * @new: new region to insert
+ * @regions: list of regions
+ *
+ * The new element is sorted by address with respect to the other
+ * regions of the same type. In case it overlaps with another
+ * region of the same type, regions are merged. In case it
+ * overlaps with another region of different type, regions are
+ * not merged.
+ */
+static int iommu_insert_resv_region(struct iommu_resv_region *new,
+				    struct list_head *regions)
+{
+	struct iommu_resv_region *region;
+	phys_addr_t start = new->start;
+	phys_addr_t end = new->start + new->length - 1;
+	struct list_head *pos = regions->next;
+
+	while (pos != regions) {
+		struct iommu_resv_region *entry =
+			list_entry(pos, struct iommu_resv_region, list);
+		phys_addr_t a = entry->start;
+		phys_addr_t b = entry->start + entry->length - 1;
+		int type = entry->type;
+
+		if (end < a) {
+			goto insert;
+		} else if (start > b) {
+			pos = pos->next;
+		} else if ((start >= a) && (end <= b)) {
+			if (new->type == type)
+				goto done;
+			else
+				pos = pos->next;
+		} else {
+			if (new->type == type) {
+				phys_addr_t new_start = min(a, start);
+				phys_addr_t new_end = max(b, end);
+
+				list_del(&entry->list);
+				entry->start = new_start;
+				entry->length = new_end - new_start + 1;
+				iommu_insert_resv_region(entry, regions);
+			} else {
+				pos = pos->next;
+			}
+		}
+	}
+insert:
+	region = iommu_alloc_resv_region(new->start, new->length,
+					 new->prot, new->type);
+	if (!region)
+		return -ENOMEM;
+
+	list_add_tail(&region->list, pos);
+done:
+	return 0;
+}
+
+static int
+iommu_insert_device_resv_regions(struct list_head *dev_resv_regions,
+				 struct list_head *group_resv_regions)
+{
+	struct iommu_resv_region *entry;
+	int ret;
+
+	list_for_each_entry(entry, dev_resv_regions, list) {
+		ret = iommu_insert_resv_region(entry, group_resv_regions);
+		if (ret)
+			break;
+	}
+	return ret;
+}
+
+int iommu_get_group_resv_regions(struct iommu_group *group,
+				 struct list_head *head)
+{
+	struct iommu_device *device;
+	int ret = 0;
+
+	mutex_lock(&group->mutex);
+	list_for_each_entry(device, &group->devices, list) {
+		struct list_head dev_resv_regions;
+
+		INIT_LIST_HEAD(&dev_resv_regions);
+		iommu_get_resv_regions(device->dev, &dev_resv_regions);
+		ret = iommu_insert_device_resv_regions(&dev_resv_regions, head);
+		iommu_put_resv_regions(device->dev, &dev_resv_regions);
+		if (ret)
+			break;
+	}
+	mutex_unlock(&group->mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_get_group_resv_regions);
+
+static ssize_t iommu_group_show_resv_regions(struct iommu_group *group,
+					     char *buf)
+{
+	struct iommu_resv_region *region, *next;
+	struct list_head group_resv_regions;
+	char *str = buf;
+
+	INIT_LIST_HEAD(&group_resv_regions);
+	iommu_get_group_resv_regions(group, &group_resv_regions);
+
+	list_for_each_entry_safe(region, next, &group_resv_regions, list) {
+		str += sprintf(str, "0x%016llx 0x%016llx %s\n",
+			       (long long int)region->start,
+			       (long long int)(region->start +
+						region->length - 1),
+			       iommu_group_resv_type_string[region->type]);
+		kfree(region);
+	}
+
+	return (str - buf);
+}
+
 static IOMMU_GROUP_ATTR(name, S_IRUGO, iommu_group_show_name, NULL);
 
+static IOMMU_GROUP_ATTR(reserved_regions, 0444,
+			iommu_group_show_resv_regions, NULL);
+
 static void iommu_group_release(struct kobject *kobj)
 {
 	struct iommu_group *group = to_iommu_group(kobj);
@@ -212,6 +355,11 @@ struct iommu_group *iommu_group_alloc(vo
 	 */
 	kobject_put(&group->kobj);
 
+	ret = iommu_group_create_file(group,
+				      &iommu_group_attr_reserved_regions);
+	if (ret)
+		return ERR_PTR(ret);
+
 	pr_debug("Allocated group %d\n", group->id);
 
 	return group;
@@ -318,7 +466,7 @@ static int iommu_group_create_direct_map
 					      struct device *dev)
 {
 	struct iommu_domain *domain = group->default_domain;
-	struct iommu_dm_region *entry;
+	struct iommu_resv_region *entry;
 	struct list_head mappings;
 	unsigned long pg_size;
 	int ret = 0;
@@ -331,18 +479,21 @@ static int iommu_group_create_direct_map
 	pg_size = 1UL << __ffs(domain->pgsize_bitmap);
 	INIT_LIST_HEAD(&mappings);
 
-	iommu_get_dm_regions(dev, &mappings);
+	iommu_get_resv_regions(dev, &mappings);
 
 	/* We need to consider overlapping regions for different devices */
 	list_for_each_entry(entry, &mappings, list) {
 		dma_addr_t start, end, addr;
 
-		if (domain->ops->apply_dm_region)
-			domain->ops->apply_dm_region(dev, domain, entry);
+		if (domain->ops->apply_resv_region)
+			domain->ops->apply_resv_region(dev, domain, entry);
 
 		start = ALIGN(entry->start, pg_size);
 		end   = ALIGN(entry->start + entry->length, pg_size);
 
+		if (entry->type != IOMMU_RESV_DIRECT)
+			continue;
+
 		for (addr = start; addr < end; addr += pg_size) {
 			phys_addr_t phys_addr;
 
@@ -358,7 +509,7 @@ static int iommu_group_create_direct_map
 	}
 
 out:
-	iommu_put_dm_regions(dev, &mappings);
+	iommu_put_resv_regions(dev, &mappings);
 
 	return ret;
 }
@@ -563,6 +714,19 @@ struct iommu_group *iommu_group_get(stru
 EXPORT_SYMBOL_GPL(iommu_group_get);
 
 /**
+ * iommu_group_ref_get - Increment reference on a group
+ * @group: the group to use, must not be NULL
+ *
+ * This function is called by iommu drivers to take additional references on an
+ * existing group.  Returns the given group for convenience.
+ */
+struct iommu_group *iommu_group_ref_get(struct iommu_group *group)
+{
+	kobject_get(group->devices_kobj);
+	return group;
+}
+
+/**
  * iommu_group_put - Decrement group reference
  * @group: the group to use
  *
@@ -845,10 +1009,19 @@ struct iommu_group *iommu_group_get_for_
 	 * IOMMU driver.
 	 */
 	if (!group->default_domain) {
-		group->default_domain = __iommu_domain_alloc(dev->bus,
-							     IOMMU_DOMAIN_DMA);
+		struct iommu_domain *dom;
+
+		dom = __iommu_domain_alloc(dev->bus, iommu_def_domain_type);
+		if (!dom && iommu_def_domain_type != IOMMU_DOMAIN_DMA) {
+			dev_warn(dev,
+				 "failed to allocate default IOMMU domain of type %u; falling back to IOMMU_DOMAIN_DMA",
+				 iommu_def_domain_type);
+			dom = __iommu_domain_alloc(dev->bus, IOMMU_DOMAIN_DMA);
+		}
+
+		group->default_domain = dom;
 		if (!group->domain)
-			group->domain = group->default_domain;
+			group->domain = dom;
 	}
 
 	ret = iommu_group_add_device(group, dev);
@@ -1557,20 +1730,38 @@ int iommu_domain_set_attr(struct iommu_d
 }
 EXPORT_SYMBOL_GPL(iommu_domain_set_attr);
 
-void iommu_get_dm_regions(struct device *dev, struct list_head *list)
+void iommu_get_resv_regions(struct device *dev, struct list_head *list)
 {
 	const struct iommu_ops *ops = dev->bus->iommu_ops;
 
-	if (ops && ops->get_dm_regions)
-		ops->get_dm_regions(dev, list);
+	if (ops && ops->get_resv_regions)
+		ops->get_resv_regions(dev, list);
 }
 
-void iommu_put_dm_regions(struct device *dev, struct list_head *list)
+void iommu_put_resv_regions(struct device *dev, struct list_head *list)
 {
 	const struct iommu_ops *ops = dev->bus->iommu_ops;
 
-	if (ops && ops->put_dm_regions)
-		ops->put_dm_regions(dev, list);
+	if (ops && ops->put_resv_regions)
+		ops->put_resv_regions(dev, list);
+}
+
+struct iommu_resv_region *iommu_alloc_resv_region(phys_addr_t start,
+						  size_t length, int prot,
+						  enum iommu_resv_type type)
+{
+	struct iommu_resv_region *region;
+
+	region = kzalloc(sizeof(*region), GFP_KERNEL);
+	if (!region)
+		return NULL;
+
+	INIT_LIST_HEAD(&region->list);
+	region->start = start;
+	region->length = length;
+	region->prot = prot;
+	region->type = type;
+	return region;
 }
 
 /* Request that a device is direct mapped by the IOMMU */
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -410,6 +410,8 @@ static struct iommu_group *mtk_iommu_dev
 		data->m4u_group = iommu_group_alloc();
 		if (IS_ERR(data->m4u_group))
 			dev_err(dev, "Failed to allocate M4U IOMMU group\n");
+	} else {
+		iommu_group_ref_get(data->m4u_group);
 	}
 	return data->m4u_group;
 }
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -502,6 +502,8 @@ static struct iommu_group *mtk_iommu_dev
 		data->m4u_group = iommu_group_alloc();
 		if (IS_ERR(data->m4u_group))
 			dev_err(dev, "Failed to allocate M4U IOMMU group\n");
+	} else {
+		iommu_group_ref_get(data->m4u_group);
 	}
 	return data->m4u_group;
 }
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -28,6 +28,7 @@ int iommu_dma_init(void);
 
 /* Domain management interface for IOMMU drivers */
 int iommu_get_dma_cookie(struct iommu_domain *domain);
+int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base);
 void iommu_put_dma_cookie(struct iommu_domain *domain);
 
 /* Setup call for arch DMA mapping code */
@@ -67,6 +68,7 @@ int iommu_dma_mapping_error(struct devic
 
 /* The DMA API isn't _quite_ the whole story, though... */
 void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg);
+void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
 
 #else
 
@@ -83,6 +85,11 @@ static inline int iommu_get_dma_cookie(s
 	return -ENODEV;
 }
 
+static inline int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
+{
+	return -ENODEV;
+}
+
 static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
 {
 }
@@ -91,6 +98,10 @@ static inline void iommu_dma_map_msi_msg
 {
 }
 
+static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
+{
+}
+
 #endif	/* CONFIG_IOMMU_DMA */
 #endif	/* __KERNEL__ */
 #endif	/* __DMA_IOMMU_H */
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -117,18 +117,32 @@ enum iommu_attr {
 	DOMAIN_ATTR_MAX,
 };
 
+/* These are the possible reserved region types */
+enum iommu_resv_type {
+	/* Memory regions which must be mapped 1:1 at all times */
+	IOMMU_RESV_DIRECT,
+	/* Arbitrary "never map this or give it to a device" address ranges */
+	IOMMU_RESV_RESERVED,
+	/* Hardware MSI region (untranslated) */
+	IOMMU_RESV_MSI,
+	/* Software-managed MSI translation window */
+	IOMMU_RESV_SW_MSI,
+};
+
 /**
- * struct iommu_dm_region - descriptor for a direct mapped memory region
+ * struct iommu_resv_region - descriptor for a reserved memory region
  * @list: Linked list pointers
  * @start: System physical start address of the region
  * @length: Length of the region in bytes
  * @prot: IOMMU Protection flags (READ/WRITE/...)
+ * @type: Type of the reserved region
  */
-struct iommu_dm_region {
+struct iommu_resv_region {
 	struct list_head	list;
 	phys_addr_t		start;
 	size_t			length;
 	int			prot;
+	enum iommu_resv_type	type;
 };
 
 #ifdef CONFIG_IOMMU_API
@@ -150,9 +164,9 @@ struct iommu_dm_region {
  * @device_group: find iommu group for a particular device
  * @domain_get_attr: Query domain attributes
  * @domain_set_attr: Change domain attributes
- * @get_dm_regions: Request list of direct mapping requirements for a device
- * @put_dm_regions: Free list of direct mapping requirements for a device
- * @apply_dm_region: Temporary helper call-back for iova reserved ranges
+ * @get_resv_regions: Request list of reserved regions for a device
+ * @put_resv_regions: Free list of reserved regions for a device
+ * @apply_resv_region: Temporary helper call-back for iova reserved ranges
  * @domain_window_enable: Configure and enable a particular window for a domain
  * @domain_window_disable: Disable a particular window for a domain
  * @domain_set_windows: Set the number of windows for a domain
@@ -184,11 +198,12 @@ struct iommu_ops {
 	int (*domain_set_attr)(struct iommu_domain *domain,
 			       enum iommu_attr attr, void *data);
 
-	/* Request/Free a list of direct mapping requirements for a device */
-	void (*get_dm_regions)(struct device *dev, struct list_head *list);
-	void (*put_dm_regions)(struct device *dev, struct list_head *list);
-	void (*apply_dm_region)(struct device *dev, struct iommu_domain *domain,
-				struct iommu_dm_region *region);
+	/* Request/Free a list of reserved regions for a device */
+	void (*get_resv_regions)(struct device *dev, struct list_head *list);
+	void (*put_resv_regions)(struct device *dev, struct list_head *list);
+	void (*apply_resv_region)(struct device *dev,
+				  struct iommu_domain *domain,
+				  struct iommu_resv_region *region);
 
 	/* Window handling functions */
 	int (*domain_window_enable)(struct iommu_domain *domain, u32 wnd_nr,
@@ -233,9 +248,14 @@ extern phys_addr_t iommu_iova_to_phys(st
 extern void iommu_set_fault_handler(struct iommu_domain *domain,
 			iommu_fault_handler_t handler, void *token);
 
-extern void iommu_get_dm_regions(struct device *dev, struct list_head *list);
-extern void iommu_put_dm_regions(struct device *dev, struct list_head *list);
+extern void iommu_get_resv_regions(struct device *dev, struct list_head *list);
+extern void iommu_put_resv_regions(struct device *dev, struct list_head *list);
 extern int iommu_request_dm_for_dev(struct device *dev);
+extern struct iommu_resv_region *
+iommu_alloc_resv_region(phys_addr_t start, size_t length, int prot,
+			enum iommu_resv_type type);
+extern int iommu_get_group_resv_regions(struct iommu_group *group,
+					struct list_head *head);
 
 extern int iommu_attach_group(struct iommu_domain *domain,
 			      struct iommu_group *group);
@@ -253,6 +273,7 @@ extern void iommu_group_remove_device(st
 extern int iommu_group_for_each_dev(struct iommu_group *group, void *data,
 				    int (*fn)(struct device *, void *));
 extern struct iommu_group *iommu_group_get(struct device *dev);
+extern struct iommu_group *iommu_group_ref_get(struct iommu_group *group);
 extern void iommu_group_put(struct iommu_group *group);
 extern int iommu_group_register_notifier(struct iommu_group *group,
 					 struct notifier_block *nb);
@@ -439,16 +460,22 @@ static inline void iommu_set_fault_handl
 {
 }
 
-static inline void iommu_get_dm_regions(struct device *dev,
+static inline void iommu_get_resv_regions(struct device *dev,
 					struct list_head *list)
 {
 }
 
-static inline void iommu_put_dm_regions(struct device *dev,
+static inline void iommu_put_resv_regions(struct device *dev,
 					struct list_head *list)
 {
 }
 
+static inline int iommu_get_group_resv_regions(struct iommu_group *group,
+					       struct list_head *head)
+{
+	return -ENODEV;
+}
+
 static inline int iommu_request_dm_for_dev(struct device *dev)
 {
 	return -ENODEV;
